Gas and fume disposal system for internal combustion engines



Oqt. 23, 1962 w. J. LINN GAS AND FUME DISPOSAL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Dec. 13, 1960 2 Sheets-Sheet 1 JNVENTOR. WILLIAM J. LINN.

M mrm ATTORNEYS.

Oct. 23, 1962 w. J. LINN 3,059,628

GAS AND FUME DISPOSAL SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Dec. 13, 1960 2 Sheets-Sheet 2 INVENTOR. WlLLlAM J. LINN BY M,%

ATTORNEYS.

United States ta This invention relates to internal combustion engines, particularly four-cycle engines, and is for a carburetion system for reducing annoying gases and fumes and smoke incident to the operation of such engines.

The invention is particularly applicable for use in connection with engines that operate at variable speeds, such as automobiles, tractors, and trucks, but is not limited to such use.

In operation of four-cycle engines, hydrocarbon vapors, carbon monoxide, and fumes, smoke and gases of various kinds are accumulated in the crank case, and a breather is provided for the escape of such gaseous substances to the atmosphere. Likewise such gaseous accumulations form under the valve covers and must be vented. These objectionable gases or vapors are often generated to a point where they are disagreeably apparent in the truck cab or an automobile. The condition is aggravated in vehicles because, when an engine is running at driving speeds and the operator removes his foot from the accelerator, as when he goes down a grade, the closing of the throttle, which substantially restricts air fioW through the carburetor to the intake manifold and engine cylinders, results in a high degree of vacuum in the intake manifold, increasing the tendency of the engine to suck oil from the crank case and oil circulating systems into the cylinders. When the throttle is opened, air is again supplied to the manifold, and oil in the cylinders is inadequately burned or vaporized. This manifests itself, especially in older engines, in a volume of smoke being discharged from the exhaust pipe when the throttle is opened, and to a lesser extent in the production of gases and vapors under the valve covers and in the crank case.

It has heretofore been proposed to conduct gases and fumes from under the valve covers and from the crank case to the intake manifold by pipes arranged for this purpose, these pipes including spring-loaded valves that partially restrict the flow of air and vapors through the pipes when pressure in the intake manifold drops down below a certain level. Such systems, however, may create so much suction in the lines as to draw oil out of the crank case or lubricating system, and it is not unusual to find the spark plugs wet with oil and vapors after the engine has been running at high speed and then throttled down due to liquids and vapors being pulled through the system. into the cylinders. Also the spring-loaded valves required to reduce flow through the pipes become fouled after a period of use and fail to function properly.

The present invention provides a system for conducting gases, certain vapors, smoke or the like from within the valve cover and the crank case to a point below the idling jet of the carburetor in which provision is made for bleeding a metered or controlled flow of atmospheric air into the system, so that even though a vacuum of the order of 26 inches may exist in the manifold, the vacuum in the lines leading from the valve covers and breather or crank case will not exceed a predetermined maximum, perhaps somewhere between 1 /2 and 7 inches. This is insufficient to cause oil or oil spray being sucked from the crank case or valve lubricating system into the manifold. The invention further contemplates bleeding the air into the system in a manner to break up and carburet the hydrocarbons in the system and introduce them into the manifold to facilitate their being mingled with the gas and air mixture from the carburetor and burned with the motor fuel. The invention further contemplates introducing the gases and fumes conducted away from the valve covers and breather into the manifold through a venturi which produces an aspirating eifect to pull the gases to be burned and the air in desirably proportioned amounts and mix them and expel them at high velocity into the intake manifold.

My invention may be more fully understood by reference to the accompanying drawings, wherein:

FIG. 1 is a schematic view showing diagrammatically the application of my invention to a V-8 type of engine with a single carburetor. Only so much of the entire engine has been schematically outlined as is necessary to understand the invention.

FIG. 2 is a similar view showing schematically the invention applied to an engine having the cylinders in line;

FIG. 3 is a top plan view of a fitting removed from association with the engine, and which constitutes the important part of the invention, a part only of its mounting plate being shown;

FIG. 4 is a vertical section of the fitting in the plane of line IV-IV of FIG. 3;

FIG. 5 is a view similar to FIG. 4 showing a valved air intake on the fitting;

FIG. 6 is a view similar to FIG. 4 showing a springloaded air intake valve;

FIG. 7 is a view similar to FIG. 4 wherein the venturi is omitted; and

FIG. 8 is a view similar to FIG. 2 of another modification.

Referring to the drawings, and first to FIG. 1, those parts of a V-8 four-cycle engine of conventional construction necessary to an understanding of the present invention are schematically illustrated, A being a carburetor with an air filter B at the top, and which is positioned between two rows of cylinders extending upwardly at divergent angles, only the valve covers C and C at the tops of the rows of cylinders being shown. The carburetor A is between the two rows of cylinders and opens into a twin manifold structure D. A breather E is schematically indicated, this breather opening into the usual closed or sealed crank case (not shown) below the cylinder. This is all a well-known engine construction forming no part per se of this invention.

According to the present invention, a mounting plate 2 is secured in position at the bottom of the carburetor between the carburetor and the intake manifold. This mounting plate comes just under the idling jet which is near the bottom of the downdraft carburetor and below the throttle plate. The plate constitutes in effect an extension of the bottom end of the carburetor and can be bolted into place by the same bolts that secure the carburetor to the manifold.

A fitting, designated generally as 3, is screwed into a hole tapped through a side wall of the mounting plate. This fitting has a nipple '4 screwed into the mounting plate, a body 5 having a passage 6 therethrough crosswise of the nipple with a tube or pipe coupling 7 at each end. A second nipple 8 is provided on the body opposite the nipple 4. The opening through the nipple 4 into the mounting plate is preferably in the form of a venturi having a throat portion 9 intermediate its ends with the passage flaring outwardly in each direction from the throat portion.

As shown in F156. 1, a pipe or tube 10 leads from one coupling 7 to one valve cover C of the V-8 engine, and a similar pipe or tube 10 leads from the other coupling 7 air and fuel entering the intake manifold from the carburetor through the plate 2. However, with this arrangement, a sudden reduction in pressure in the manifold would greatly increase the suction in pipes 19, and 11, to a point where oil could be pulled in excessive amounts into the fitting.

With the present invention in its simplest form, a hole 12 is provided in the body of the fitting at a point where it will open into the passage 6 in front of the second nipple 8 and rearwardly of the nipple 4, this opening or port being open to the atmosphere. The size of the port or hole 12 is predetermined so that under all conditions of operation a suction or negative pressure will be maintained in the pipes 10, 10 and 11, but not exceed a predetermined maximum value, say between 1 /2 and 7 inches of vacuum.

The hole, at the location described, will introduce the air directly into the converging streams of vapors and gases from the pipes 16, 10' and 11 slightly in front of the venturi. In this location it carburets hydrocarbons in these streams and mixes with them, while the venturi form of passage in the nipple 3 better induces a flow and mixing of air with gas and vapors and projects the mixture at high velocity into the passage through the plate 2 to thoroughly mingle with the air and gas mixture from the carburetor. It functions also to maintain the suction through pipes 10, 10 and 11 and port 12 substantially constant under varying degrees of vacuum in the manifold above a minimum.

Tests have established that under severe conditions of accelerating and decelerating the engine spark plugs will remain dry, whereas in other systems now available, under similar conditions of operation, the spark plugs, after such a test, will be wet or badly fouled.

Where the fitting is provided on an engine having the cylinders in line, one of the couplings 7 may be replaced with a plug, so that the fitting is universally adaptable to V-type and in-line engines. This is indicated in FIG. 2 where corresponding reference numerals have been used to indicate corresponding parts, except that in this view D is the entrance to a single manifold instead of a double manifold as in FIG. 1. The pipe 10 leads from one of the couplings 7 of the fitting 3 to the single valve cover C, and pipe 11 leads as in FIG. 1, to the breather pipe, while the other coupling 7 of the fitting is replaced with a plug 100.

In the modification shown in FIG. 5, the construction of the fitting is essentially the same as that shown in FIG. 1, there being a body 13 with a nipple 14 designed to screw into a mounting plate such as 2. Opposite the nipple 14 is a second nipple 15 for connection with the pipe 11 as in FIGS. 1 or 2. There is a passageway through the nipple 14- in the form of a venturi, and there is a passageway 16 through the valve body corresponding to the passageway 6 to accommodate a pipe coupling at one or both ends, or as in FIG. 2, a plug at one end. The air inlet port from the atmosphere is shown at 17. There is a needle valve 18 screwewd into the valve body opposite the port 17 with a tapered terminal that projects into the port so that the infiow of atmospheric air through the port 17 can be readily adjusted.

In the construction shown in FIG. 6, the fitting is essentially the same as in FIG. 3, there being a body 20 similar to the body 3, with a nipple 21 corresponding to the nipple 4. The body has a longitudinal passageway 25 therethrough, and there is a second nipple 26 opposite the nipple 21 and corresponding to the nipple 8 of FIG. 3. The air inlet port, corresponding to 12, is designated 27, but there is a valve casing 23 screwed into this port within which is a ball valve 29 that is urged outwardly by a spring 30. The spring biases the hall to a normally closed position, but when a predetermined degree of vacuum forms in the manifold and in the carburetor below the throttle plate, the suction will unseat the ball 29 and allow atmospheric air to flow through the port 27. The

spring is set to open under a very light suction so that under all normal conditions of operation the ball valve will be unseated and admit air.

While I prefer in all cases to form the passage through the nipple 4 or the corresponding nipples '14 or 21 in FIGS. 5 and 6 as a venturi, some of the benefits of the present invention can be secured by making a passageway into the fitting 2 a straight passageway. This is indicated in FIG. 7 which shows a fitting shaped similarly to FIGS. 3 and 4, the fitting being designated generally as 31, with a nipple 32 adapted to be screwed into the mounting plate 2, and which has a straight passageway 33 therethrough. There is a passageway 34 through the body transverse to the passage 33, and which may be provided with conplings at each end, or a coupling and a plug as in FIG. 3, and there is a nipple 35 opposite the first nipple 32. The air inlet port is designated 36, and it is located in the same relative position as the port 12 in FIG. 3. The arrangement shown in FIG. 7 might of course be used with the needle valve 18 as in FIG. 5, or the springbiased valve as in FIG. 6.

While I have shown and described certain specific embodiments of my invention, it will be understood that various other modifications and changes may be made to effect the same purpose. In each case, provision is made for drawing gases and fumes from the valve cover or covers of the engine, and from the crank case into a common passageway where they are mixed with each other and with atmospheric air, and then are discharged into the intake manifold at the lower end of the carburetor. The passageway through which atmospheric air is introduced into the vapors and gases from the valve covers and crank case is located where the gases and vapors from the pipes 10' and 11, or 10, 10' and 11 converge, and in slightly spaced relation back of the venturi as in FIGS. 4, 5 and 6, or back of the passage 33 through the nipple 32 as in FIG. 7. This provides for a more effective introduction of the air and mixing of the gases and vapors with the air, and the insweep of air at this location also aids in preventing the fitting from becoming clogged. Not only is the introduction of air at this point desirable from the standpoint of carbureting gases and vapors withdrawn from the valve covers and crank case, but because of the bleeding of atmospheric air into the system, the suction in the lines 10, 10' and 11 can never exceed a predetermined maximum, whereby sucking of oil into the system from the engine is precluded. Because of the removal of vapors and gases from the crank case and valve covers through the system, these products do not collect under the hood or ditfuse into the interior of the automobile or truck cab.

As above pointed out, the system can be easily applied to an engine because the mounting plate 2 can be connected between the bottom of the carburetor and the intake of the manifold to form in effect an extension of the carburetor. Because of the introduction of air and gases through this system it is usually necessary to make some change in the idling adjustment of the carburetor when the system is installed.

When an engine is operating, the oil in the crank case is violently churned, agitated and splashed, resulting in the formation of tiny drops that coalesce and drop back into the crank case. This mist of droplets is not to be confused with fumes, heat-generated vapors, hydrocarbon gases resulting from vaporizing volatile substances in the oil and partially oxidized gases. With the present invention, using a venturi in the fitting and a properly selected air opening, the maximum degree of suction in the pipes 10, 10' and 11 can be controlled, so as to substantially eliminate the withdrawal of this mist While removing gases and fumes. I have mentioned a range between 1 /2 inches and 7 inches as being satisfactory, but this is only by way of example and may range from some appreciable fraction of an inch upwardly to a level where sucking of oil would be evident.

It should also be mentioned that with my system the crank case breather is plugged or sealed against the escape of fumes or the influx of substantial volumes of air, and if there is a vented oil filler cap it, too, should be sealed, so that the crank case will be closed against free influx of air, so that pipe 11 does not function as simply an air duct.

I have found that in some engines, particularly engines of large horsepower, a positive pressure may build up in the crank case where the arrangement shown in FIGS. 1 and 2 is used, with the breather plugged and the engine turning over at high speed. This results from the inability of the attachment as shown in FIGS. 1 and 2 to take care of the large volume of crank case gases that may be present in such an engine. In FIG. 8 I have shown a modification which may be used on all engines, but which is particularly desirable in engines where this condition is encountered. In this figure the general arrangement is the same as that shown in FIGS. 1 and 2, A indicating the carburetor, and B is the air cleaner; C is a valve cover, and D is the intake manifold, while B is the breather. There is an insert plate 2 similar to plate 2 in FIGS. 1 and 2 on which is the fitting 3 cor responding to the construction described in connection with FIGS. 1 and 2 and shown in detail in FIGS. 3 to 7, and as shown in FIG. 2 there is a pipe 1% leading from one branch of the fitting 3 to the valve cover, or in the case of a V engine, the arrangement would be as shown in FIG. 1 with tubes 10 leading to each of the other valve covers. In the arrangement shown in FIG. 8, however, instead of a pipe 11 leading directly from the breather to one branch of the fitting 3, I pro vide a tube or pipe 35 leading from the breather to the air filter B. Intermediate the ends of the tube 35 I provide a T-connection 36 having a branch 37 that is connected to a nipple corresponding to the nipple 8 of FIGS. 3 and 4. The T-connection 36 in the pipe 35 is preferably at a level above the breather E and below the air filter, and it is spaced from both the filter and breather close to midway between the breather and the air filter, preferably a little closer to the air filter than to the breather.

When the engine is running with the throttle wide open, there is of course a suction of air through the filter into the carburetor. Consequently smoke and gases that are not drawn through the tube 37 into the fitting 3 in the manner described in connection with FIGS. 1 and 2 will be drawn into the air filter to mingle with the atmospheric air entering the carburetor, and the smoke and gases will thus be thoroughly mingled with the inflowing air and pass through the carburetor into the engine cylinders. Consequently when the engine is running at high speed, all of the crank case gases will be removed, part of them through the fitment 3, and part of them passing directly to the air filter B. In this manner the tendency of the engine to build up a positive pressure in the crank case is relieved. When the throttle is closed, there is a small flow of air through the air filter, and there is an increase of suction in the intake manifold, so that at this time all of the gases and fumes which are then being generated at a lower rate because of the lower speed of the engine will pass through the branch pipe 37 and into the fitting 3 to be injected into the air-fuel mixture below the throttle in the manner described in connection with FIGS. 1 and 2.

It is desirable to place the T-connection 36 at a point removed from the breather pipe B so that oil mist which may be entrained with the gases will have an opportunity to agglomerate in the tube 35 below the T 36 and drain as a liquid back into the crank case. It is desirable that the T-connection 36 be removed from the air intake B so as to reduce the amount of atmospheric air which might flow in the reverse direction from the air filter through the T- connection 36 into the pipe 37 when the throttle is closed. In other words, the location of the fitting 36 too close to the air filter B would tend to reduce the effectiveness of the fitting 3 in removing gases and fumes from the crank case when the engine is running with the throttle closed. Experiment has shown that the location .of the T intermediate the ends of the tube 35 preferably slightly closer to the air filter B than to the breather E, is most desirable.

In the drawings I have indicated threaded connections for the use of metallic tubing, but I have found that rubber tubing and cemented connections may be used equally well, and with less cost and less care required in the installation, because metal tubing must be carefully bent to shape, whereas the rubber tubing will readily adapt itself to the contours which it must follow. As above indicated, in FIG. 8 I have shown an arrangement similar to FIG. 2 in which there is only one valve cover, and one branch of the fitting 3 is closed with a plug 10a as in FIG. 2, but the arrangement shown in FIG. 8 may be just as well used with the arrangement shown in FIG. 1. In FIGS. 1, 2 and 8 a throttle is schematically indicated at F.

Test installations on road vehicles where fumes in the cab have been particularly noticeable have proved the effectiveness of this invention with an incidental improvement in engine performance and reduction of smoke at the discharge of the tail pipe. Improved engine performance can be explained by reference to one condition of operation. Assume a car is being driven up a hill at full open throttle and a sharp curve is encountered. At full open throttle a maximum discharge of gasoline into the carburetor is occurring. The operator, encountering the curve, lifts his foot from the throttle, closing off the free flow of air to the manifold, and there is a residue of wet gasoline in the manifold. The operator again opens the throttle and the engine momentarily manifest the same sluggish response that is evident when a choke valve fails to open. The inflow of air and gases through the use of this invention will partly relieve the lack of air from the closing of the throttle and the engine will accelerate smoothly when the throttle is next open. By reducing carbon monoxide, smoke and fumes, the invention benefits not only the driver, but contributes to the benefit of others, especially on heavily traveled thoroughfares, where these fumes are detrimental to the eyes, nose, throat and health of others driving or walking along the same thoroughfare.

I may use to good advantage the fitting herein described in connection with a mounting embodying a circular series of small venturi as disclosed in my Patent No. 2,889,214, but this is optional.

I claim:

1. For use with internal combustion engines, an integral multi-branched fitting, each branch having a passageway therethrough terminating in the fitting at a common juncture, one branch having a venturi therein between its extremities and the point of common juncture of the passageways, the fitting having a bleed port therein that opens to the atmosphere and which extends from the exterior of the fitting to the juncture of the several passageways, said first-named branch having a terminal for connection with the air intake system of an engine, the other branches providing connections for separate tubes that may connect with the crank case and valve hoods of an engine respectively.

2. In an internal combustion engine having a crank case, an air intake system, a carburetor in the air intake system having a throttle, the engine having also a valve cover, the invention comprising a multi-b-ranched fitting having one branch opening into the air intake system at the engine side of the carburetor, said branch having a venturi therein, a second branch of the fitting having a tube that is connected with the crank case of the engine and another branch of the fitting having a tube that communicates with the interior of the valve cover, said fitting also having a bleed opening therethrough from the atmosphere to the interior of the fitting at a point adjacent the point where the first branch joins into the fitting of which it 7 is a part, the venturi being located between said port and the terminal end of the branch in which it is located.

3. In an internal combustion engine having valve covers, a breather pipe, a carburetor and an intake manifold, the invention comprising a fitting having a pipe leading to the valve cover and a pipe leading to the breather, said fitting having a passageway therein into which both of said pipes deliver smoke and gases, the fitting having an outlet connection opening into the intake manifold through which gases and vapors may flow from said passageway into said manifold, the outlet connection comprising a venturi with a throat intermediate the ends of said connection with an outwardly-flaring passageway at each side of the throat, one flaring passageway opening into the manifold and the other opening into said first passageway in the fitting, the fitting having a bleed port to atmosphere opening into said passageway where the gases and vapors from the two pipes converge in said passageway and forwardly relatively to the direction of gas flow of the venturi in the outlet connection.

4. In an internal combustion engine having valve covers, a breather pipe, a carburetor and an intake manifold, the invention comprising a fitting having a pipe leading to the valve cover and a pipe leading to the breather, said fitting having a passageway therein into which both of said pipes deliver vapors and gases, the fitting having an outlet connection opening into the intake manifold through which gases and smoke may flow from said passageway into said manifold, the outlet connection comprising a venturi with a throat intermediate the ends of said connection with an outwardly-flaring passageway at each side of the throat, one flaring passageway opening into the manifold and the other opening into said first passageway in the fitting, the fitting having a bleed port to atmosphere opening into said passageway where the gases and vapors from the two pipes converge in said passageway and forwardly relatively to the direction of gas flow through the fitting of the venturi in the outlet connection, said bleed port having a valve therein for regulating air flow therethrough.

5. The invention defined in claim 1 wherein said air admission port has a valve therein for regulating the flow of air therethrough.

6. The invention defined in claim 1 wherein said air admission port has a valve therein for regulating the flow of air therethrough, the valve being manually adjustable.

7. The invention defined in claim 1 wherein said air admission port has a valve therein for regulating the flow of air therethrough, the valve being spring-biased to closed position.

8. A fitting for use on either V-type or in-line multiple cylinder internal combustion engines wherein the engine has a carburetor, an intake manifold with an inlet, a valve cover for each set of cylinders and a crank case breather, the fitting comprising a body having a passageway therethrough with a pipe connection at one end and means at the other end to receive alternatively a pipe connection and a plug, the body having an outlet nipple with a venturi therein, the inner end of the venturi opening into said passageway, the body having another nipple opposite the, first for another pipe connection, the body having an air bleed port located between the first and second nipples into said passageway, a mounting member into which the outlet nipple is entered and through which smoke and gases are discharged from the fitting into the intake manifold, a pipe leading from said second nipple to the crank case breather, a pipe leading from the coupling at one end of the passageway to one valve cover, and a second pipe leading from said means at the other end of the passageway only when the engine has a second valve cover and which receives a plug when the engine has but a single valve cover, said mounting member being fixed between the lower end of the carburetor and the manifold inlet.

9. Means for reducing the discharge of smoke, fumes and carbon monoxide into the air from the breather and valve covers of internal combustion engines comprising a duct for attachment to each valve cover and another duct leading from the crank case breather, a fitting to which said ducts connect having a common passage into which gases from the ducts converge, said fitting having an outlet connection for mounting on the engine intake manifold, and discharging gases into the manifold, said connection having a venturi-shaped passage therein, the fitting having an air passage therein leading from said common passage to atmosphere and located in the common passage in spaced relation to the manifold in the outlet connection.

10. Apparatus for reducing escape of smoke and fumes from an internal combustion engine wherein the engine has a carburetor, an air filter for the carburetor, an intake manifold joined to the carburetor, a valve hood and a crank case breather, which apparatus comprises a fitting for mounting at the juncture of the carburetor and intake manifold, said fitting having a discharge nipple opening into the manifold, a second nipple and a tube extending from the nipple to the interior of the cover, said fitting having a third nipple and a tube leading from said third nipple connected with the breather, the fitting having a common passage through which gases may flow from the respective tubes into the discharge nipple, said fitting also having a bleed opening from said passage to atmosphere whereby gases may be drawn through said tubes and mixed with air and discharged into the manifold when the pressure in the intake manifold is less than atmospheric pressure, said tube connected with the breather having a T- connection therein with one branch leading to the breather and one branch leading to the air filter whereby gases in the breather may be drawn into the air filter and also into said fitting when the engine is running with an open throttle.

11. Apparatus for reducing escape of smoke and fumes from an internal combustion engine wherein the engine has a carburetor, an air filter for the carburetor, an intake manifold joined to the carburetor, a valve hood and a crank case breather, which apparatus comprises a fitting for mounting at the juncture of the carburetor and intake manifold, said fitting having a discharge nipple opening into the manifold, a second nipple and a tube extending from the nipple to the interior of the cover, said fitting having a third nipple and a tube leading from said third nipple connected with the breather, the fitting having a common passage through which gases may flow from the respective tubes into the discharge nipple, said fitting also having a bleed opening from said passage to atmosphere whereby gases may be drawn through said tubes and mixed with air and discharged into the manifold when the pressure in the intake manifold is less than atmospheric pressure, said tube connected with the breather having a T-connection therein with one branch leading to the breather and one branch leading to the air filter whereby gases in the breather may be drawn into the air filter and also into said fitting when the engine is running with an open throttle, said T-connection being located in spaced relation to both the breather and the air filter and close to equidistantly from each.

References Cited in the file of this patent UNITED STATES PATENTS 2,829,629 Badertscher et al. Apr. 8, 1958 FOREIGN PATENTS 128,444 Great Britain June 26, 1919 961,034 France Nov. 14, 1949 

